import 'package:flutter/material.dart';
import '../constants.dart' show AppColors, Constants;
import './conversation_page.dart';
import './contacts_page.dart';

enum ActionItems { GROUP_CHAT, ADD_FRIEND, QR_SCAN, PAYMENT, HELP }

class NavigationIconView {
  final BottomNavigationBarItem item;

  NavigationIconView(
      {Key key, String title, IconData icon, IconData activeIcon})
      : item = BottomNavigationBarItem(
            icon: Icon(icon),
            activeIcon: Icon(activeIcon),
            title: Text(title),
            backgroundColor: Colors.white);
}

class HomeScreen extends StatefulWidget {
  @override
  _HomeScreenState createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  PageController _pageController;
  int _currentIndex = 0;
  List<NavigationIconView> _navigationViews;
  List<Widget> _pages;

  @override
  void initState() {
    super.initState();
    _navigationViews = [
      NavigationIconView(
          title: '微信',
          icon: IconData(0xe608, fontFamily: Constants.IconFontFamily),
          activeIcon: IconData(0xe603, fontFamily: Constants.IconFontFamily)),
      NavigationIconView(
        title: '通讯录',
        icon: IconData(
          0xe600,
          fontFamily: Constants.IconFontFamily,
        ),
        activeIcon: IconData(
          0xe648,
          fontFamily: Constants.IconFontFamily,
        ),
      ),
      NavigationIconView(
        title: '发现',
        icon: IconData(
          0xe602,
          fontFamily: Constants.IconFontFamily,
        ),
        activeIcon: IconData(
          0xe601,
          fontFamily: Constants.IconFontFamily,
        ),
      ),
      NavigationIconView(
        title: '我',
        icon: IconData(
          0xe64d,
          fontFamily: Constants.IconFontFamily,
        ),
        activeIcon: IconData(
          0xe64c,
          fontFamily: Constants.IconFontFamily,
        ),
      ),
    ];
    _pageController = PageController(initialPage: _currentIndex);
    _pages = [
      // Container(color: Colors.red),
      ConversationPage(),
      // Container(color: Colors.green),
      ContactsPage(),
      Container(color: Colors.blue),
      Container(color: Colors.brown),
    ];
  }

  _buildPopupMunuItem(int icon, String title) {
    return Row(
      children: <Widget>[
        Icon(
          IconData(icon, fontFamily: Constants.IconFontFamily),
          size: 22.0,
          color: const Color(AppColors.AppBarPopupMenuColor),
        ),
        Container(
          width: 12.0,
        ),
        Text(
          title,
          style: TextStyle(color: const Color(AppColors.AppBarPopupMenuColor)),
        ),
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    final BottomNavigationBar botNavBar = BottomNavigationBar(
      fixedColor: const Color(AppColors.TabIconActive),
      items: _navigationViews
          .map<BottomNavigationBarItem>((NavigationIconView view) => view.item)
          .toList(),
      currentIndex: _currentIndex,
      type: BottomNavigationBarType.fixed,
      onTap: (int index) {
        setState(() {
          _currentIndex = index;
          _pageController.animateToPage(_currentIndex,
              duration: Duration(milliseconds: 200), curve: Curves.easeOut);
        });
      },
    );

    return Scaffold(
      appBar: AppBar(
        title: Text('微信'),
        elevation: 0.0,
        actions: <Widget>[
          Container(
            padding: const EdgeInsets.only(right: 16.0),
            child: IconButton(
              icon: Icon(Icons.search),
              onPressed: () {
                print('点击了搜索按钮');
              },
            ),
          ),
          PopupMenuButton(
            itemBuilder: (BuildContext context) {
              return <PopupMenuItem<ActionItems>>[
                PopupMenuItem(
                  child: _buildPopupMunuItem(0xe69e, "发起群聊"),
                  value: ActionItems.GROUP_CHAT,
                ),
                PopupMenuItem(
                  child: _buildPopupMunuItem(0xe638, "添加朋友"),
                  value: ActionItems.ADD_FRIEND,
                ),
                PopupMenuItem(
                  child: _buildPopupMunuItem(0xe623, "扫一扫"),
                  value: ActionItems.QR_SCAN,
                ),
                PopupMenuItem(
                  child: _buildPopupMunuItem(0xe62a, "收付款"),
                  value: ActionItems.PAYMENT,
                ),
                PopupMenuItem(
                  child: _buildPopupMunuItem(0xe63d, "帮助与反馈"),
                  value: ActionItems.HELP,
                ),
              ];
            },
            icon: Icon(
              Icons.add,
              size: 22.0,
            ),
            onSelected: (ActionItems selected) {
              print(selected);
            },
          ),
          Container(width: 16.0),
        ],
      ),
      body: PageView.builder(
        itemBuilder: (BuildContext context, int index) {
          return _pages[index];
        },
        controller: _pageController,
        itemCount: _pages.length,
        onPageChanged: (int index) {
          print('当前显示的地$index页');
          setState(() {
            _currentIndex = index;
          });
        },
      ),
      bottomNavigationBar: botNavBar,
    );
  }
}
